“Electrical grid” or “grid,” as used herein, refers to a Wide Area Synchronous Grid (also known as an Interconnection), and is a regional scale or greater electric power grid that that operates at a synchronized frequency and is electrically tied together during normal system conditions. An electrical grid delivers electricity from generation stations to consumers. An electrical grid includes: (i) generation stations that produce electrical power at large scales for delivery through the grid, (ii) high voltage transmission lines that carry that power from the generation stations to demand centers, and (iii) distribution networks carry that power to individual customers.
FIG. 1 illustrates a typical electrical grid, such as a North American Interconnection or the synchronous grid of Continental Europe (formerly known as the UCTE grid). The electrical grid of FIG. 1 can be described with respect to the various segments that make up the grid.
A generation segment 102 includes one or more generation stations that produce utility-scale electricity (typically >50 MW), such as a nuclear plant 102a, a coal plant 102b, a wind power station (i.e., wind farm) 102c, and/or a photovoltaic power station (i.e., a solar farm) 102d. Generation stations are differentiated from building-mounted and other decentralized or local wind or solar power applications because they supply power at the utility level and scale (>50 MW), rather than to a local user or users. The primary purpose of generation stations is to produce power for distribution through the grid, and in exchange for payment for the supplied electricity. Each of the generation stations 102a-d includes power generation equipment 102e-h, respectively, typically capable of supply utility-scale power (>50 MW). For example, the power generation equipment 102g at wind power station 102c includes wind turbines, and the power generation equipment 102h at photovoltaic power station 102d includes photovoltaic panels.
Each of the generation stations 102a-d may further include station electrical equipment 102i-1 respectively. Station electrical equipment 102i-1 are each illustrated in FIG. 1 as distinct elements for simplified illustrative purposes only and may, alternatively or additionally, be distributed throughout the power generation equipment, 102e-h, respectively. For example, at wind power station 102c, each wind turbine may include transformers, frequency converters, power converters, and/or electrical filters. Energy generated at each wind turbine may be collected by distribution lines along strings of wind turbines and move through collectors, switches, transformers, frequency converters, power converters, electrical filters, and/or other station electrical equipment before leaving the wind power station 102c. Similarly, at photovoltaic power station 102d, individual photovoltaic panels and/or arrays of photovoltaic panels may include inverters, transformers, frequency converters, power converters, and/or electrical filters. Energy generated at each photovoltaic panel and/or array may be collected by distribution lines along the photovoltaic panels and move through collectors, switches, transformers, frequency converters, power converters, electrical filters, and/or other station electrical equipment before leaving the photovoltaic power station 102d. 
Each generation station 102a-d may produce AC or DC electrical current which is then typically stepped up to a higher AC voltage before leaving the respective generation station. For example, wind turbines may typically produce AC electrical energy at 600V to 700V, which may then be stepped up to 34.5 kV before leaving the generation station 102d. In some cases, the voltage may be stepped up multiple times and to a different voltage before exiting the generation station 102c. As another example, photovoltaic arrays may produce DC voltage at 600V to 900V, which is then inverted to AC voltage and may be stepped up to 34.5 kV before leaving the generation station 102d. In some cases, the voltage may be stepped up multiple times and to a different voltage before exiting the generation station 102d. 
Upon exiting the generation segment 102, electrical power generated at generation stations 102a-d passes through a respective Point of Interconnection (“POI”) 103 between a generation station (e.g., 102a-d) and the rest of the grid. A respective POI 103 represents the point of connection between a generation station's (e.g. 102a-d) equipment and a transmission system (e.g., transmission segment 104) associated with electrical grid. In some cases, at the POI 103, generated power from generation stations 102a-d may be stepped up at transformer systems 103e-h to high voltage scales suitable for long-distance transmission along transmission lines 104a. Typically, the generated electrical energy leaving the POI 103 will be at 115 kV AC or above, but in some cases it may be as low as, for example, 69 kV for shorter distance transmissions along transmission lines 104a. Each of transformer systems 103e-h may be a single transformer or may be multiple transformers operating in parallel or series and may be co-located or located in geographically distinct locations. Each of the transformer systems 103e-h may include substations and other links between the generation stations 102a-d and the transmission lines 104a. 
A key aspect of the POI 103 is that this is where generation-side metering occurs. One or more utility-scale generation-side meters 103a-d (e.g., settlement meters) are located at settlement metering points at the respective POI 103 for each generation station 102a-d. The utility-scale generation-side meters 103a-d measure power supplied from generation stations 102a-d into the transmission segment 104 for eventual distribution throughout the grid.
For electricity consumption, the price consumers pay for power distributed through electric power grids is typically composed of, among other costs, Generation, Administration, and Transmission & Distribution (“T&D”) costs. T&D costs represent a significant portion of the overall price paid by consumers for electricity. These costs include capital costs (land, equipment, substations, wire, etc.), costs associated with electrical transmission losses, and operation and maintenance costs.
For utility-scale electricity supply, operators of generation stations (e.g., 102a-d) are paid a variable market price for the amount of power the operator generates and provides to the grid, which is typically determined via a power purchase agreement (PPA) between the generation station operator and a grid operator. The amount of power the generation station operator generates and provides to the grid is measured by utility-scale generation-side meters (e.g., 103a-d) at settlement metering points. As illustrated in FIG. 1, the utility-scale generation-side meters 103a-d are shown on a low side of the transformer systems 103e-h), but they may alternatively be located within the transformer systems 103e-h or on the high side of the transformer systems 103e-h. A key aspect of a utility-scale generation-side meter is that it is able to meter the power supplied from a specific generation station into the grid. As a result, the grid operator can use that information to calculate and process payments for power supplied from the generation station to the grid. That price paid for the power supplied from the generation station is then subject to T&D costs, as well as other costs, in order to determine the price paid by consumers.
After passing through the utility-scale generation-side meters in the POI 103, the power originally generated at the generation stations 102a-d is transmitted onto and along the transmission lines 104a in the transmission segment 104. Typically, the electrical energy is transmitted as AC at 115 kV+ or above, though it may be as low as 69 kV for short transmission distances. In some cases, the transmission segment 104 may include further power conversions to aid in efficiency or stability. For example, transmission segment 104 may include high-voltage DC (“HVDC”) portions (along with conversion equipment) to aid in frequency synchronization across portions of the transmission segment 104. As another example, transmission segment 104 may include transformers to step AC voltage up and then back down to aid in long distance transmission (e.g., 230 kV, 500 kV, 765 kV, etc.).
Power generated at the generation stations 104a-d is ultimately destined for use by consumers connected to the grid. Once the energy has been transmitted along the transmission segment 104, the voltage will be stepped down by transformer systems 105a-c in the step down segment 105 so that it can move into the distribution segment 106.
In the distribution segment 106, distribution networks 106a-c take power that has been stepped down from the transmission lines 104a and distribute it to local customers, such as local sub-grids (illustrated at 106a), industrial customers, including large EV charging networks (illustrated at 106b), and/or residential and retail customers, including individual EV charging stations (illustrated at 106c). Customer meters 106d, 106f measure the power used by each of the grid-connected customers in distribution networks 106a-c. Customer meters 106d are typically load meters that are unidirectional and measure power use. Some of the local customers in the distribution networks 106a-d may have local wind or solar power systems 106e owned by the customer. As discussed above, these local customer power systems 106e are decentralized and supply power directly to the customer(s). Customers with decentralized wind or solar power systems 106e may have customer meters 106f that are bidirectional or net-metering meters that can track when the local customer power systems 106e produce power in excess of the customer's use, thereby allowing the utility to provide a credit to the customer's monthly electricity bill. Customer meters 106d, 106f differ from utility-scale generation-side meters (e.g., settlement meters) in at least the following characteristics: design (electro-mechanical or electronic vs current transformer), scale (typically less than 1600 amps vs. typically greater than 50 MW; typically less than 600V vs. typically greater than 14 kV), primary function (use vs. supply metering), economic purpose (credit against use vs payment for power), and location (in a distribution network at point of use vs. at a settlement metering point at a Point of Interconnection between a generation station and a transmission line).
To maintain stability of the grid, the grid operator strives to maintain a balance between the amount of power entering the grid from generation stations (e.g., 102a-d) and the amount of grid power used by loads (e.g., customers in the distribution segment 106). In order to maintain grid stability and manage congestion, grid operators may take steps to reduce the supply of power arriving from generation stations (e.g., 102a-d) when necessary (e.g., curtailment). Particularly, grid operators may decrease the market price paid for generated power to dis-incentivize generation stations (e.g., 102a-d) from generating and supplying power to the grid. In some cases, the market price may even go negative such that generation station operators must pay for power they allow into the grid. In addition, some situations may arise where grid operators explicitly direct a generation station (e.g., 102a-d) to reduce or stop the amount of power the station is supplying to the grid.
Power market fluctuations, power system conditions (e.g., power factor fluctuation or generation station startup and testing), and operational directives resulting in reduced or discontinued generation all can have disparate effects on renewal energy generators and can occur multiple times in a day and last for indeterminate periods of time. Curtailment, in particular, is particularly problematic.
According to the National Renewable Energy Laboratory's Technical Report TP-6A20-60983 (March 2014):                [C]urtailment [is] a reduction in the output of a generator from what it could otherwise produce given available resources (e.g., wind or sunlight), typically on an involuntary basis. Curtailments can result when operators or utilities command wind and solar generators to reduce output to minimize transmission congestion or otherwise manage the system or achieve the optimal mix of resources. Curtailment of wind and solar resources typically occurs because of transmission congestion or lack of transmission access, but it can also occur for reasons such as excess generation during low load periods that could cause baseload generators to reach minimum generation thresholds, because of voltage or interconnection issues, or to maintain frequency requirements, particularly for small, isolated grids. Curtailment is one among many tools to maintain system energy balance, which can also include grid capacity, hydropower and thermal generation, demand response, storage, and institutional changes. Deciding which method to use is primarily a matter of economics and operational practice.        “Curtailment” today does not necessarily mean what it did in the early 2000s. Two separate changes in the electric sector have shaped curtailment practices since that time: the utility-scale deployment of wind power, which has no fuel cost, and the evolution of wholesale power markets. These simultaneous changes have led to new operational challenges but have also expanded the array of market-based tools for addressing them.        Practices vary significantly by region and market design. In places with centrally-organized wholesale power markets and experience with wind power, manual wind energy curtailment processes are increasingly being replaced by transparent offer-based market mechanisms that base dispatch on economics. Market protocols that dispatch generation based on economics can also result in renewable energy plants generating less than what they could potentially produce with available wind or sunlight. This is often referred to by grid operators by other terms, such as “downward dispatch.” In places served primarily by vertically integrated utilities, power purchase agreements (PPAs) between the utility and the wind developer increasingly contain financial provisions for curtailment contingencies.        Some reductions in output are determined by how a wind operator values dispatch versus non-dispatch. Other curtailments of wind are determined by the grid operator in response to potential reliability events. Still other curtailments result from overdevelopment of wind power in transmission-constrained areas.        Dispatch below maximum output (curtailment) can be more of an issue for wind and solar generators than it is for fossil generation units because of differences in their cost structures. The economics of wind and solar generation depend on the ability to generate electricity whenever there is sufficient sunlight or wind to power their facilities.        Because wind and solar generators have substantial capital costs but no fuel costs (i.e., minimal variable costs), maximizing output improves their ability to recover capital costs. In contrast, fossil generators have higher variable costs, such as fuel costs. Avoiding these costs can, depending on the economics of a specific generator, to some degree reduce the financial impact of curtailment, especially if the generator's capital costs are included in a utility's rate base.        
Curtailment may result in available energy being wasted because solar and wind operators have zero variable cost (which may not be true to the same extent for fossil generation units which can simply reduce the amount of fuel that is being used). With wind generation, in particular, it may also take some time for a wind farm to become fully operational following curtailment. As such, until the time that the wind farm is fully operational, the wind farm may not be operating with optimum efficiency and/or may not be able to provide power to the grid.